#!/bin/bash

function scandir() {
	local cur_dir parent_dir workdir
	workdir=$1
	cd ${workdir}
	if [ ${workdir} == "/" ]; then
		cur_dir=""
	else
		cur_dir=$(pwd)
	fi

	for dirlist in $(ls ${cur_dir}); do
		if test -d ${dirlist}; then
			cd ${dirlist}
			scandir ${cur_dir}/${dirlist} $2
			cd ..
		else
			local filename=$dirlist
			if [[ ${filename:(-${#2})} = $2 ]]; then
				exist=$(cat $filename | sed -n '1p' | grep '#coding:utf-8')
				if [[ -z $exist ]]; then
					echo "modifying file:"$filename
					sed -i 1'i\#coding:utf-8' $filename
				fi

			fi
		fi
	done
}

if test -d $1; then
	scandir $1 $2
elif test -f $1; then
	echo "you input a file but not a directory,pls reinput and try again"
	exit 1
else
	echo "the Directory isn't exist which you input,pls input a new one!!"
	exit 1
fi
